Answer by Dale Blundell (Atkins)
The installation cost of a heat pump system, especially ground source heat pumps, will be considerably more than that of conventional alternatives. The inconvenience of retrofitting the heat distribution system to existing buildings should also be taken account of.
A typical domestic Air source heat pump will cost €10 - 15,000.
A typical domestic ground source heat pump will cost €15-21,000.
A commercial size heat pump would typically cost in the region of €550-700 per kW of heat output, not including the heat collection and distribution systems.
The lifetime of a heat pump installation is typically over 25 years, helping to offset the greater installation cost. Maintenance requirements are minimal, with professional inspection only needed perhaps every 3 years. The householder should periodically check that the external heat exchanger is not blocked by any debris or plant growth. The system pressure gauge should also be periodically checked so as to detect any leaks.